Film bag

ABSTRACT

A film bag having a bag body is formed with two front walls. A first lateral edge, which is formed by at least the two front walls, is connected at a first corner of the bag body to an upper bag edge. At the upper bag edge, the two front walls are interconnected by a fastening seam. Each of the front walls has, at the first corner, multiple lines of weakness that extend, in a curve and spaced from each other, from the first lateral edge up to the fastening seam. A tear-open aid is situated on the fastening seam. At least three lines of weakness are provided. The tear-open aid is designed and situated in such a way that the aid allows for a tearing-open, at the upper bag edge, between any two adjacent lines of weakness.

CROSS-REFERENCE TO A RELATED APPLICATION

The invention described and claimed hereinbelow is also described in German Priority Document DE 10 2016 100 824.9, filed on Jan. 19, 2016. The German Priority Document, the subject matter of which is incorporated herein by reference, provides the basis for a claim of priority of invention under 35 U.S.C. 119(a)-(d).

BACKGROUND OF THE INVENTION

The invention relates to a film bag having a bag body comprising two front walls, wherein a first lateral edge, which is formed from at least the two front walls, is connected at a first corner of the bag body to an upper bag edge, at which the two front walls are interconnected by a fastening seam. Each of the front walls comprises, at the first corner, multiple lines of weakness which extend, in a curve and spaced from each other, from the first lateral edge up to the fastening seam. A tear-open aid is situated on the fastening seam.

Film bags are opened in highly diverse ways in practical use. In addition to being cut open using a knife or a pair of scissors, film bags also are intended to be opened by hand.

For example, it is known to use multi-layer coextruded films or composite films for forming film bags, in the case of which the two opposing front walls can be opened by peeling open, i.e., separating, a fastening seam on the upper bag edge. Such a separation can take place either by the seal being opened or by a material failure within the layered composite, wherein either an adhesive failure or a co-adhesive failure results. Suitable opening patterns also can be achieved in film bags, in the case of which an upper bag edge is closed by an adhesive.

The type of opening described is frequently utilized in the area of snack packagings, such as those used for potato chips, for example. In this case, the entire upper bag edge is usually opened and, therefore, the contents of the film bag are easily grasped by hand.

In addition, different types of tear-open aids and opening aids are known.

A zigzag cut on the upper bag edge allows for an easy tearing-open. Suitable tear-open aids such as individual indentations, tear-open notches, or a zigzag cut allow for a simple initiation of tearing. Further tearing-open by a user, however, is difficult to control, even when oriented film layers made from oriented polyethylene terephthalate (OPET) or biaxially oriented polypropylene (BO-PP) allow for easy tearing. Even if a user can deliberately control a tear in the case of the aforementioned materials, a certain amount of skill is required on the part of the user to tear open in a specific way. The same also applies for cellulose-based films, which also have considerable stiffness without a biaxial orientation.

In addition, opening aids in the form of lines of weakness created by a laser or by a punch in the material are known from practical application. Such lines of weakness make it possible to precisely predefine the course of the tear and the opening formed thereby. In addition, easy handling during tearing-opening also is ensured.

WO 2012/100 996 A1 describes a film bag, in the case of which multiple lines of weakness are situated at a first corner of the bag, body between a first lateral edge and an upper bag edge, which lines converge and thereby form a single line of weakness.

Due to the measures described, an opening having a consistent size and a consistent tear pattern always result. The embodiment described also is suitable, to an extent, for tearing open side-gusseted bags, in which the lateral fold has been inserted between the two front walls, beginning at the upper bag edge. Before the inserted lateral fold is reached, the different lines of weakness converge.

US 2012/0273 493 A1 describes a film bag, in the case of which either the entire upper bag edge or only one corner can be torn off. Different lines of weakness or weakened line sections are provided for this purpose, wherein the course of the tear is controlled by the tear-initiation. To tear open the entire upper bag edge, the tear-initiation takes place at one of the lateral edges. Against this background, to tear off only one corner, the tear-initiation takes place either beginning at the opposite lateral edge or at the upper bag edge. To select the different tear-open options, a high-level of attentiveness on the part of the user is necessary, wherein incorrect handling cannot be ruled out with certainty.

According to DE 20 2009 000 302 U1, multiple lines of weakness are provided, wherein the tear-initiation takes place on a central line of weakness and the tear is then taken over by outwardly-lying lines of weakness.

According to CA 2 689 258 C, two lines of weakness extend over each other in a transverse direction of a film bag, wherein, due to a suitable sealing on the upper bag edge, either only a portion or the entire width of the bag can be opened. The manufacturing of the bag is complicated, however, because large areas must be sealed to achieve the described functionality. In this case as well, incorrect handling can result in the film bag being inadvertently completely opened.

EP 2 650 229 A1 and CN 202 609 252 U relate to further embodiments, in the case of which a packaging can be successively further torn open, for the purpose of which the corresponding lines of weakness are arranged parallel to each other in a straight orientation.

Finally, a film bag having the features described at the outset is known from U.S. Pat. No. 8,740,458 B2. As disclosed therein, a tear-open aid in the form of a tear-open notch is provided at an upper bag edge, wherein, starting at the tear-open aid, the tear initially proceeds, unguided, along the front walls during a tearing-open, before the tear reaches a curved line of weakness and, from there, is guided to a lateral edge of the bag body. A second line of weakness situated therebelow is used as protection for the case in which the tear inadvertently diverges from the first line of weakness. If the initially unguided tear follows the line of weakness, an angulation along the course thereof results. The risk of an uncontrolled tearing-open exists precisely at such angulations. To ensure that the tear can follow the line of weakness, the line must weaken the material to a suitably great extent. The size of the opening that is formed must not be influenced. The tear extends initially from the tear-open aid approximately straight downward and then transitions into the line of weakness and, therefore, the same dimensions of the opening always result during a tearing-open.

SUMMARY OF THE INVENTION

The present invention overcomes the shortcomings of known arts, such as those mentioned above by providing a film bag that can be torn open particularly easily and in a particularly flexible manner.

In an embodiment, the inventive film bag has a bag body comprising two front walls. A first lateral edge, which is formed from at least the two front walls, is connected at a first corner of the bag body to an upper bag edge, at which the two front walls are interconnected by a fastening seam. Each of the front walls comprises, at the first corner, lines of weakness that extend, in a curve and spaced from each other, from the first lateral edge at least up to the fastening seam. A tear-open aid is situated on the fastening seam. At least three lines of weakness are provided on each front wall and the tear-open aid is designed and situated in such a way that the aid allows for a tearing-open, at the upper bag edge, between any two adjacent lines of weakness and/or precisely at each line of weakness.

According to the invention, at least three lines of weakness are provided on each front wall and the tear-open aid is designed and situated in such a way that the aid allows for a tearing-open, at the upper bag edge, between any two adjacent lines of weakness and/or precisely at each line of weakness.

The size of the opening can be influenced by a user to a certain extent by the at least three lines of weakness extending at a distance from each other. If only one small opening is required, it is only necessary to tear open one relatively small corner section. If a larger opening is desired, however, it is possible to utilize the tear-open aid to tear open along a line of weakness situated closer to the center of the bag, whereby a larger corner section is therefore removed. The film bag also can be subsequently torn open to a larger extent, if so desired by a user.

Specifically, in the case of a liquid or pourable product, handling directly after the tearing-open can at times be difficult due to the weight of the bag. In the case of a bag which has been filled to the brim, it can be difficult to remove small quantities by tilting the bag, due to the internal pressure. A relatively small opening is advantageous, therefore, specifically at the beginning of the withdrawal of the product.

Subsequently, the inventive bag can then be torn open further, to allow the remaining product to be quickly withdrawn. In this case, it must be taken into account that a bag which has already been partially emptied is easier to handle due to the low weight thereof, wherein the product itself can develop less momentum during pouring as well.

The creation of a differently sized opening also can be advantageous to either remove only portions or to allow the bag to be emptied all at once as quickly as possible.

The film bag according to the invention may be used for highly diverse pourable products. These include, for example, foodstuffs such as rice, sugar, flour, cereals, pelleted animal feed, highly diverse powdered or granular construction products, detergents and cleaning agents, cat litter, or the like.

Since the tear-open aid makes it possible to tear open between adjacent lines of weakness and/or precisely at each line of weakness, an uncontrolled tearing-open is also prevented. Immediately after the tearing-open, the tear will jump over to one of the two adjacent lines of weakness, and therefore the tear is then guided along a predefined course.

According to the invention, the lines of weakness extend in a curve between the first lateral edge and the upper bag edge, wherein the lines of weakness advantageously have a convex shape beginning at the first corner.

If the bag is torn open beginning at the upper edge using the tear-open aid, the convex course of the lines of weakness beginning at the first corner corresponds to the usual direction in which a user tears, and therefore the tearing-open can take place particularly easily and reliably.

According to an embodiment, it is provided that all lines of weakness, at the end thereof assigned to the upper edge, enclose an angle of more than 60° with the upper bag edge. Preferably, the angle is greater than 75°, being approximately 90°, for example. If the tear is then initially formed, at the tear-open aid using two hands, at an approximately right angle downward from the upper bag edge, this course of the tear also corresponds to the course of the lines of weakness, and therefore a strong angulation does not result when the tear, which has formed in this way, is transferred to one of the lines of weakness, and the tearing-open can take place in one easy, fluid motion.

The lines of weakness formed on the two front walls are preferably arranged to mutually overlap, wherein production-related deviations can be accepted, depending on the design. A precise or at least largely precise overlap of the lines of weakness at the two front walls results when the first lateral edge is designed as a fold edge and the lines of weakness are created symmetrically relative to this fold line, which is easily possible during the production of the film bag, for example, using a form-fill-seal (FFS) method.

Preferably, between 5 and 10 lines of weakness extending at a distance from each other are provided on each of the front walls, to achieve a very high level of comfort and flexibility for the user in a way that is as easy as possible to manufacture. Depending on the specific requirements, however, only three or four as well as more than eleven lines of weakness can be provided. Specifically, in the case of large bags, a greater number of lines of weakness on the two front walls can be advantageous, to achieve a greater level of flexibility in terms of the sizes of the opening to be formed.

According to an embodiment, the lines of weakness are arranged in the shape of a curve, at different distances from each other, about a common reference point. For example, the lines of weakness can be designed as circular arcs or elliptical arcs having a common center point.

For example, the lines of weakness can extend, as quarter circles, concentrically about a center point which is situated on the first corner or about a center point which is situated to be offset relative to the first corner.

Preferably, the lines of weakness are situated equidistantly from each other, and therefore adjacent lines of weakness have an identical separation. Independently of a precisely equidistance arrangement, the separation between adjacent lines of weakness is preferably between 7 mm and 30 mm, for example, 10 mm or 14 mm. If the lines of weakness are arranged, for example, as circular arcs, concentrically about one center point, the radius continuously increases according to the separation between adjacent lines of weakness.

Without restriction, the lines of weakness can be created by a laser or a punch. Within this context, a person skilled in the art can adapt the laser energy or the punch depth to the particular material combination and thickness.

Since an easy tearing-open is possible due to the tear-open aid and the curved course preferably also approximately corresponds to the direction in which a user tears, even relatively slight material weakenings due to the lines of weakness are sufficient for ensuring a controlled tearing-open behavior.

The tear-open aid on the upper bag edge can be formed particularly easily by a zigzag cut. Multiple indentations or notches which are situated at least in the area of the lines of weakness on the upper bag edge also are possible alternatives. Naturally, a zigzag cut, indentations, or notches also can extend in the transverse direction across the entire width of the film bag, along the upper bag edge.

In the case of a correspondingly fine design, a zigzag cut makes it possible to tear between two adjacent lines of weakness, wherein it is then not necessary to pay attention to the precise orientation of the zigzag section relative to the lines of weakness. If the tear-open aid is supposed to make it possible, additionally or alternatively, to tear open precisely at each line of weakness, then indentation or notches can be particularly preferably provided for this purpose. For example, it can be sufficient if the lines of weakness extend not only up to the fastening seam, but rather over the fastening seam and up to the outermost edge of the front walls, and therefore the lines of weakness themselves form the tear-open aid at the ends thereof. During the creation of the lines of weakness by a laser or by a punch, to create the tear-open aid, it is also possible to remove more material at the corresponding points and, if necessary, the film can be completely passed through.

Preferably, it is provided that the lines of weakness extend on the upper bag edge, beginning at the first corner, over a range between 10% and 45% of the bag width determined along the upper bag edge.

Additionally, or alternatively, on the upper bag edge, both corners can be provided with lines of weakness in the manner described, and therefore the described tear-open structure is then also present at a second corner between the upper bag edge and a second lateral edge, and the film bag can be torn open alternatively at one of the two lateral edges.

If the two front walls form a front side and a back side which are clearly apparent to a user due to the usually provided printing thereon, the film bag can be easily torn open by a right-handed person and by a left-handed person if the described lines of weakness are provided on the two upper corners.

The design of the film bag according to the invention is particularly advantageous when the bag body is formed exclusively from the two front walls and, therefore, comprises no lateral folds and, preferably, no bottom folds either. Such a pillow-shaped bag can be formed particularly easily from a tube, wherein the film bag is preferably created using the FFS method. The design of the film bag according to the invention also can be provided, however, when the bag body of the film bag is folded from a single film sheet or is formed from two film sheets by hot sealing.

Materials which are usually used for film bags are possibilities for the front walls. Preferably, the bag body is formed from a coextruded film or a film which has been laminated in multiple layers. To form the film bag and, in particular, the fastening seam at the upper bag edge by heat sealing, an inner film layer is preferably formed from a heat-sealable material such as polyolefin, in particular, polyethylene. In the case of a laminated film, oriented film layers such as OPET and BO-PP are frequently used for the outer layers. In the case of a laminated film, a printing is preferably located on an inner layer transition, so that the imprint is optimally protected.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the invention will become apparent from the description of exemplary embodiments that follows, with reference to the attached figures, wherein:

FIG. 1 shows a film bag according to the invention, before being torn open;

FIG. 2 shows a detailed view of a first corner of the film bag according to FIG. 1, directly after a tearing-open beginning at an upper bag edge; and

FIG. 3 shows the torn-open film bag according to FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

The following is a detailed description of example embodiments of the invention depicted in the accompanying drawings. The example embodiments are presented in such detail as to clearly communicate the invention and are designed to make such embodiments obvious to a person of ordinary skill in the art. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present invention, as defined by the appended claims.

FIG. 1 shows a film bag according to the invention, the bag body of which is formed from two front walls 1. The bag body formed from the two front walls comprises a first lateral edge 2 a, a second lateral edge 2 b, a lower bag edge 3, and an upper bag edge 4. The lower bag edge 3 and the upper bag edge 4 are each closed by a fastening seam in the form of a heat-sealed seam.

At the lateral edges 2 a, 2 b, the front walls 1 transition into each other via bending lines, wherein a fastening seam for the peripheral closure of the bag body is preferably situated in the center on the front wall 1 which forms the back side of the bag body and which is not visible in FIG. 1.

Alternatively, the fastening seam can be situated at one of the lateral edges 2 a, 2 b.

Multiple lines of weakness 6 are located in the area of a first corner 5 formed between the first lateral edge 2 a and the upper bag edge 4. The lines of weakness 6, in the embodiment shown, extend from the first lateral edge 2 a, in a curve and spaced from each other, up to the fastening seam at the upper bag edge 4, wherein a tear-open aid is situated on the fastening seam.

According to the detailed view from FIG. 2, a zigzag cut 7 is provided as the tear-open aid. Alternatively, multiple notches or indentations can be provided as the tear-open aid.

At least three and, in the exemplary embodiment, seven lines of weakness 6 are located on each front wall. The tear-open aid is designed and situated in such a way that said aid allows for a tearing-open, at the upper edge, between two adjacent lines of weakness 6.

By the zigzag cut 7, the upper bag edge can be torn open by a user at approximately any point (at any depth). If separate notches or indentations, for example, are provided instead of a zigzag cut 7, then such a notch or indentation can be provided at least between any two adjacent lines of weakness 6.

If the upper bag edge 4 according to FIG. 2 is torn open between two lines of weakness 6, the tear initially extends downward at an approximately right angle and can then be received by one of the adjacent lines of weakness 6.

The lines of weakness have a convex shape relative to the first corner 5 and usually enclose an angle of more than 60° with the upper bag edge 4.

The lines of weakness 6 preferably extend in the shape of a curve, at different distances from each other, about a common reference point. For example, the lines of weakness 6 can extend, as quarter circles, concentrically about a center point situated at the first corner 5, wherein an equidistant arrangement of the lines of weakness 6 is achieved by means of a uniformly increasing radius.

The distance between adjacent lines of weakness can be, for example, between 7 mm and 30 mm, being approximately 15 mm, for example.

Preferably, the lines of weakness 6 are created by a laser, wherein the formation by a punch is also a possibility. If the film bag is torn open further, proceeding from FIG. 2, a bag section having the first corner 5 is ultimately completely removed, and therefore the contents of the film bag can then be removed (FIG. 3). As should be apparent from FIG. 3, the opening can easily be enlarged by a user by removing a further, then annular section along a further line of weakness 6.

As will be evident to persons skilled in the art, the foregoing detailed description and figures are presented as examples of the invention, and that variations are contemplated that do not depart from the fair scope of the teachings and descriptions set forth in this disclosure. The foregoing is not intended to limit what has been invented, except to the extent that the following claims so limit that. 

What is claimed is:
 1. A film bag having a bag body, comprising: two front walls; wherein a first lateral edge is formed from at least the two front walls and is connected at a first corner of the bag body to an upper bag edge; wherein the two front walls are interconnected at the upper bag edge by a fastening seam; wherein each of the two front walls comprise, at the first corner of the bag body, at least three lines of weakness that extend in a curve, and that are spaced from each other, from the first lateral edge at least up to the fastening seam; and wherein a tear-open aid is designed and situated on the fastening seam to allow for a tearing-open, at the upper bag edge, between any two adjacent lines of weakness, precisely at each line of weakness or both.
 2. The film bag according to claim 1, wherein the lines of weakness have a convex shape beginning at the first corner of the bag body.
 3. The film bag according to claim 1, wherein all lines of weakness enclose an angle, at an end thereof assigned to the upper bag edge, of more than 60° with the upper bag edge.
 4. The film bag according to claim 1, wherein the lines of weakness are arranged in the shape of a curve, at different distances from each other, about a common reference point.
 5. The film bag according to claim 4, wherein the lines of weakness extend, as quarter circles, concentrically about a center point situated at the first corner.
 6. The film bag according to claim 1, wherein the lines of weakness are equidistantly arranged.
 7. The film bag according to claim 1, wherein the distance between adjacent lines of weakness is between 7 mm and 30 mm.
 8. The film bag according to claim 1, wherein the lines of weakness are created by a laser.
 9. The film bag according to claim 1, wherein the tear-open aid is formed from a zigzag cut.
 10. The film bag according to claim 1, wherein the lines of weakness extend on the upper bag edge, beginning at the first corner, over a range between 10% and 45% of the bag width determined along the upper bag edge.
 11. The film bag according to claim 1, wherein the bag body comprises further lines of weakness at a second corner formed between the upper bag edge and a second lateral edge, and wherein the further lines of weakness have a convex shape beginning at the second corner.
 12. The film bag according to claim 1, wherein the bag body is formed exclusively from the front walls. 